<!DOCTYPE HTML>
<html>

<head>
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
    <title>拖拽</title>
    <style type="text/css">
        body,
        div {
            margin: 0;
            padding: 0;
            font-size: 12px;
        }
        
        body {
            width: 960px;
            margin: 0 auto;
        }
        
        ul,
        li {
            margin: 0;
            padding: 0;
            list-style: none;
        }
        
        .clear {
            clear: both;
            width: 1px;
            height: 0px;
            line-height: 0px;
            font-size: 1px;
        }
        
        .box {
            width: 800px;
            height: auto;
            float: left;
            margin: 25px 0 0 0;
            padding: 5px;
            border: 1px solid #f00;
        }
        
        .main {
            position: static;
            float: left;
            width: 250px;
            height: 80px;
            margin-bottom: 5px;
            margin-left: 10px;
            border: 1px solid blue;
            background: #ccc;
        }
        
        .maindash {
            position: absolute;
            width: 250px;
            height: 80px;
            margin-bottom: 5px;
            border: 1px dashed blue;
            background: #ececec;
            opacity: 0.7;
        }
        
        .hide {
            width: 250px;
            height: 80px;
            margin-bottom: 5px;
        }
        
        .dash {
            position: static;
            width: 250px;
            float: left;
            height: 80px;
            margin-bottom: 5px;
            margin-left: 10px;
            border: 1px dashed #f00;
        }
        
        ;
    </style>
    <script src="https://code.jquery.com/jquery-3.1.1.js" integrity="sha256-16cdPddA6VdVInumRGo6IbivbERE8p7CQR3HzTBuELA=" crossorigin="anonymous"></script>
    <script type="text/javascript">
        $(document).ready(function() {
            var range = {
                x: 0,
                y: 0
            }; //鼠标元素偏移量
            var lastPos = {
                x: 0,
                y: 0,
                x1: 0,
                y1: 0
            }; //拖拽对象的四个坐标
            var tarPos = {
                x: 0,
                y: 0,
                x1: 0,
                y1: 0
            }; //目标元素对象的坐标初始化
            var theDiv = null,
                move = false; //拖拽对象 拖拽状态
            var theDivId = 0,
                theDivHeight = 0,
                theDivWidth = 0,
                theDivHalf = 0,
                theDivWHalf = 0,
                tarFirstX = 0,
                tarFirstY = 0; //拖拽对象的索引、高度、的初始化。
            var tarDiv = null,
                tarFirst, tempDiv, tempDiv2; //要插入的目标元素的对象, 临时的虚线对象
            $(".main").each(function() {
                $(this).mousedown(function(event) {
                    $("#eventString").html("");
                    $("#eventString2").html(""); //拖拽对象
                    theDiv = $(this); //鼠标元素相对偏移量
                    range.x = event.pageX - theDiv.offset().left;
                    range.y = event.pageY - theDiv.offset().top;
                    theDivId = theDiv.index();
                    theDivHeight = theDiv.height();
                    theDivWidth = theDiv.width();
                    theDivHalf = theDivHeight / 2;
                    theDivWHalf = theDivWidth / 2;
                    move = true;
                    theDiv.attr("class", "maindash"); // 创建新元素 插入拖拽元素之前的位置(虚线框)
                    $("<div class='dash'></div>").insertBefore(theDiv);
                    $(".dash").mouseup(function(event) {
                        $("#eventString").html("dash is mouseup");
                        theDiv.attr("class", "main");
                        if ($(".dash")) {
                            $(".dash").remove();
                        }
                        move = false;
                    });
                });
            });
            $(document).mousemove(function(event) {
                if (!move) return false;
                document.documentElement.style["WebkitUserSelect"] = "none";
                document.unselectable = "on";
                document.onselectstart = function() {
                    return false;
                }
                lastPos.x = event.pageX; //鼠标的x坐标
                lastPos.y = event.pageY; //鼠标的y坐标
                lastPos.y1 = lastPos.y + theDivHeight;
                lastPos.x1 = lastPos.x + theDivWidth; // 拖拽元素随鼠标移动
                theDiv.css({
                    left: lastPos.x + 'px',
                    top: lastPos.y + 'px'
                }); // 拖拽元素随鼠标移动 查找插入目标元素
                var $main = $('.main'); // 局部变量：按照重新排列过的顺序 再次获取 各个元素的坐标，
                tempDiv = $(".dash"); //获得临时 虚线框的对象
                $main.each(function() {
                    tarDiv = $(this);
                    tarPos.x = tarDiv.offset().left;
                    tarPos.y = tarDiv.offset().top;
                    tarPos.y1 = tarPos.y + tarDiv.height();
                    tarPos.x1 = tarPos.x + tarDiv.width();
                    tarFirst = $main.eq(0); // 获得第一个元素
                    tarFirstY = tarFirst.offset().top; // 第一个元素对象的中心纵坐标
                    tarFirstX = tarFirst.offset().left; //判断要插入目标元素的 坐标后， 直接插入
                    if (lastPos.y >= tarPos.y && lastPos.x >= tarPos.x && lastPos.y <= tarPos.y1 && lastPos.x <= tarPos.x1) {
                        var classValue = tarDiv.prev().attr("class");
                        if (classValue == "main") {
                            $("#eventString3").html("check-------" + classValue);
                        }
                        $("#eventString2").html(theDiv.prev().attr("class"));
                        if (tarDiv.prev("div").length > 0 && tarDiv.next("div").length > 0) {
                            $("#eventString2").html(tarDiv.html() + " : " + tarDiv.prev(".main").html());
                            tempDiv.insertAfter(tarDiv.prev("div"));
                        }
                        /*else if(tarDiv.prev(".dash") || tarDiv.prev(".maindash")){$("#eventString2").html(tarDiv.html());tempDiv.insertAfter(tarDiv);}*/
                        else if (tarDiv.next("div").length <= 0) {
                            $("#eventString2").html(tarDiv.html());
                            tempDiv.insertAfter(tarDiv);
                        } else {
                            tempDiv.insertBefore(tarDiv);
                        }
                    }
                });
            }).mouseup(function(event) {
                $("#eventString2").html("document is mouseup");
                theDiv.insertBefore(tempDiv); // 拖拽元素插入到 虚线div的位置上
                theDiv.attr("class", "main"); //恢复对象的初始样式
                if ($(".dash")) {
                    $(".dash").remove();
                } // 删除新建的虚线
                move = false;
            });
        });
    </script>
</head>

<body onselectionstart=“javascript:return false;”>
    <div class="box" id="box">
        <div class="main" id="main0">div1</div>
        <div class="main" id="main1">div2</div>
        <div class="main" id="main2">div3</div>
        <div class="main" id="main3">div4</div>
        <div class="main" id="main4">div5</div>
        <div class="main" id="main5">div6</div>
        <div class="main" id="main6">div7</div>
        <div class="main" id="main7">div8</div>
        <div class="main" id="main8">div9</div>
        <div class="main" id="main9">div10</div>
    </div>
    <div><span id="eventString"></span><br /><span id="eventString2"></span><br /><span id="eventString3"></span></div>
</body>

</html>
